House Minority Leader Nancy Pelosi isn't saying yet whether she endorses Hillary Clinton or Bernie Sanders for the Democratic presidential nominee, and has hinted she won't say who she supports before her home state's primary on Tuesday.

"I will make an endorsement, and I'll decide when that is," the California Democrat told reporters in San Francisco in May, reports The Hill. However, she refused to say who her choice was at that time, and still hasn't made her announcement.

She has hinted that she would like to see Clinton become the nation's first female president, but has not officially endorsed her, meaning that she's the only remaining top congressional leader to have not chosen a candidate.

Sanders and his supporters have accused the Democratic Party's leaders, including Democratic National Committee Chairwoman Debbie Wasserman Schultz, of rigging the election in Clinton's favor, and if Pelosi endorses Clinton, the talk of a rigged election could grow, reports The Hill.

Pelosi has praised both Wasserman Schultz and Sanders, calling him a "positive force" who has "awakened in some people an interest in the political process that wasn't there."

But still, she has said that Clinton is among the best-prepared presidential candidates there has ever been and refers to the next president as "whoever she may be."

Many other key Democrats have refused to endorse a Democratic candidate until after a nominee is named, including President Barack Obama and Vice-President Joe Biden, former Vice President Al Gore, and Massachusetts Sen. Elizabeth Warren.

Some Democrats, like Reid, waited until Clinton won their state's' primaries before announcing their endorsements, so Pelosi's may come after Tuesday.

House Minority Leader Nancy Pelosi isn't saying yet whether she endorses Hillary Clinton or Bernie Sanders for the Democratic presidential nominee, and has hinted she won't say who she supports before her home state's primary on Tuesday.